Letzkus et al.
Supplementary Figure 1:
30
BEE
number of total responses (n)
REE
LEE
25
BEC
N = 33
20
N = 36
N = 25
15
10
N = 25
5
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20
Trial #
Supplementary Figure 1: Number of total responses for each trial. All in all 119
animals were trained (= N). The figure shows that the number of total responses (= n)
did not change massively, although altogether ten bees (8.4%) died after the first ten
trials and thus the overall number of trained animals was reduced slightly. If the dead
bees had previously extended their proboscis in more than 60% of the trials, they were
included in the analysis.
7 bees (5.4%) did not extend their proboscis at all in more than 60% of the trials and
were excluded from analysis.
Supplementary Figure 2:
0.6
BEC
Proportion of correct responses
BEE
0.5
REE
LEE
0.4
0.3
0.2
0.1
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Trial #
Supplementary Figure 2: Learning performance of each group at each training
trial. This figure shows that a plateau of performance is starting to form in the last
two training trials for the LEE and REE groups. REE-bees show a performance of
52% in trials 19 and 20. LEE-bees show a performance of 14% in trial 19 and 15% in
trial 20.
Two more trials were conducted for all three groups (BEE, REE, LEE; data not
shown). Unfortunately, conducting more than ten trials on the second training day
resulted in a ‘false’ growth of the learning curves because, although the bees which
had learned the PER task still responded to the conditioned stimulus (CS), many of
the bees which had not learned the task did not extend their proboscis after touching
their mouthparts due to lack of motivation after ten previous trials. This resulted in a
higher response rate, not because more bees actually learned the task, but rather
because less bees responded to the unconditioned stimulus (US). This was true for all
groups.
The experiment could not be continued on the third day, because of a mortality rate of
50% or greater.